At the time of decimalisation in 1971, the United Kingdom Crown coin (equal to 5 shillings) was redenominated as a 25p coin and pieces struck prior to 1990 - all the way back to 1818 - continue to be legal tender for that amount. The old denomination had been a regular circulating coin in the 19th century, but in the 20th century it became more of a commemorative denomination.
The Royal Mint continued issuing commemorative coins in the same format - using the traditional coin dimensions, but in copper-nickel. These were initially also denominated as 25 pence but the "Crown" was changed in 1990 to a commemorative £5 (five pound) coin, having the same dimensions and weight but with a face value twenty times as great.
The denomination is used to mark special occasions, usually royal in theme, rather than for use in general circulation. Although not circulating, these coins are legal tender.
This commemorative £5 Crown-sized coin celebrates the christening of Prince George, the first son of the Duke and Duchess of Cambridge.
Prince George of Cambridge (George Alexander Louis) was born on 22 July 2013. He is the eldest child of Prince William, Duke of Cambridge, and Catherine, Duchess of Cambridge, and third in the line of succession to the British throne behind his grandfather (Prince Charles) and his father. As he is one day expected to become king, his birth was widely celebrated across the Commonwealth realms.
Prince George was baptised by the Archbishop of Canterbury in the Chapel Royal at St James's Palace on 23 October 2013. The font used at the ceremony was made for Queen Victoria's first child and the water was taken from the River Jordan.
Earlier the same year, the Royal Mint had released another Crown coin celebrating the birth of Prince George. | 
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